Message-ID: <20140306214927.GB11171@cmpxchg.org>
Date:	Thu, 6 Mar 2014 16:49:27 -0500
From:	Johannes Weiner <hannes@...xchg.org>
To:	akpm@...ux-foundation.org
Cc:	mm-commits@...r.kernel.org, stable@...nel.org, riel@...hat.com,
	mgorman@...e.de, jstancek@...hat.com, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: Re: [merged]
 mm-page_alloc-reset-aging-cycle-with-gfp_thisnode-v2.patch removed from -mm
 tree

Hey Andrew,

On Thu, Mar 06, 2014 at 12:37:57PM -0800, akpm@...ux-foundation.org wrote:
> Subject: [merged] mm-page_alloc-reset-aging-cycle-with-gfp_thisnode-v2.patch removed from -mm tree
> To: hannes@...xchg.org,jstancek@...hat.com,mgorman@...e.de,riel@...hat.com,stable@...nel.org,mm-commits@...r.kernel.org
> From: akpm@...ux-foundation.org
> Date: Thu, 06 Mar 2014 12:37:57 -0800
> 
> 
> The patch titled
>      Subject: mm: page_alloc: exempt GFP_THISNODE allocations from zone fairness
> has been removed from the -mm tree.  Its filename was
>      mm-page_alloc-reset-aging-cycle-with-gfp_thisnode-v2.patch
> 
> This patch was dropped because it was merged into mainline or a subsystem tree

Would it make sense to also merge

mm-fix-gfp_thisnode-callers-and-clarify.patch

at this point?  It's not as critical as the GFP_THISNODE exemption,
which is why I didn't tag it for stable, but it's a bugfix as well.

> ------------------------------------------------------
> From: Johannes Weiner <hannes@...xchg.org>
> Subject: mm: page_alloc: exempt GFP_THISNODE allocations from zone fairness
> 
> Jan Stancek reports manual page migration encountering allocation failures
> after some pages when there is still plenty of memory free, and bisected
> the problem down to 81c0a2bb515f ("mm: page_alloc: fair zone allocator
> policy").
> 
> The problem is that GFP_THISNODE obeys the zone fairness allocation
> batches on one hand, but doesn't reset them and wake kswapd on the other
> hand.  After a few of those allocations, the batches are exhausted and the
> allocations fail.
> 
> Fixing this means either having GFP_THISNODE wake up kswapd, or
> GFP_THISNODE not participating in zone fairness at all.  The latter seems
> safer as an acute bugfix, we can clean up later.
> 
> Reported-by: Jan Stancek <jstancek@...hat.com>
> Signed-off-by: Johannes Weiner <hannes@...xchg.org>
> Acked-by: Rik van Riel <riel@...hat.com>
> Acked-by: Mel Gorman <mgorman@...e.de>
> Cc: <stable@...nel.org>		[3.12+]
> Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
> ---
> 
>  mm/page_alloc.c |   26 ++++++++++++++++++++++----
>  1 file changed, 22 insertions(+), 4 deletions(-)
> 
> diff -puN mm/page_alloc.c~mm-page_alloc-reset-aging-cycle-with-gfp_thisnode-v2 mm/page_alloc.c
> --- a/mm/page_alloc.c~mm-page_alloc-reset-aging-cycle-with-gfp_thisnode-v2
> +++ a/mm/page_alloc.c
> @@ -1238,6 +1238,15 @@ void drain_zone_pages(struct zone *zone,
>  	}
>  	local_irq_restore(flags);
>  }
> +static bool gfp_thisnode_allocation(gfp_t gfp_mask)
> +{
> +	return (gfp_mask & GFP_THISNODE) == GFP_THISNODE;
> +}
> +#else
> +static bool gfp_thisnode_allocation(gfp_t gfp_mask)
> +{
> +	return false;
> +}
>  #endif
>  
>  /*
> @@ -1574,7 +1583,13 @@ again:
>  					  get_pageblock_migratetype(page));
>  	}
>  
> -	__mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
> +	/*
> +	 * NOTE: GFP_THISNODE allocations do not partake in the kswapd
> +	 * aging protocol, so they can't be fair.
> +	 */
> +	if (!gfp_thisnode_allocation(gfp_flags))
> +		__mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
> +
>  	__count_zone_vm_events(PGALLOC, zone, 1 << order);
>  	zone_statistics(preferred_zone, zone, gfp_flags);
>  	local_irq_restore(flags);
> @@ -1946,8 +1961,12 @@ zonelist_scan:
>  		 * ultimately fall back to remote zones that do not
>  		 * partake in the fairness round-robin cycle of this
>  		 * zonelist.
> +		 *
> +		 * NOTE: GFP_THISNODE allocations do not partake in
> +		 * the kswapd aging protocol, so they can't be fair.
>  		 */
> -		if (alloc_flags & ALLOC_WMARK_LOW) {
> +		if ((alloc_flags & ALLOC_WMARK_LOW) &&
> +		    !gfp_thisnode_allocation(gfp_mask)) {
>  			if (zone_page_state(zone, NR_ALLOC_BATCH) <= 0)
>  				continue;
>  			if (!zone_local(preferred_zone, zone))
> @@ -2503,8 +2522,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, u
>  	 * allowed per node queues are empty and that nodes are
>  	 * over allocated.
>  	 */
> -	if (IS_ENABLED(CONFIG_NUMA) &&
> -			(gfp_mask & GFP_THISNODE) == GFP_THISNODE)
> +	if (gfp_thisnode_allocation(gfp_mask))
>  		goto nopage;
>  
>  restart:
> _
> 
> Patches currently in -mm which might be from hannes@...xchg.org are
> 
> origin.patch
> mm-vmscan-respect-numa-policy-mask-when-shrinking-slab-on-direct-reclaim.patch
> mm-vmscan-move-call-to-shrink_slab-to-shrink_zones.patch
> mm-vmscan-remove-shrink_control-arg-from-do_try_to_free_pages.patch
> mm-vmstat-fix-up-zone-state-accounting.patch
> mm-vmstat-fix-up-zone-state-accounting-fix.patch
> fs-cachefiles-use-add_to_page_cache_lru.patch
> lib-radix-tree-radix_tree_delete_item.patch
> mm-shmem-save-one-radix-tree-lookup-when-truncating-swapped-pages.patch
> mm-filemap-move-radix-tree-hole-searching-here.patch
> mm-fs-prepare-for-non-page-entries-in-page-cache-radix-trees.patch
> mm-fs-prepare-for-non-page-entries-in-page-cache-radix-trees-fix.patch
> mm-fs-store-shadow-entries-in-page-cache.patch
> mm-thrash-detection-based-file-cache-sizing.patch
> lib-radix_tree-tree-node-interface.patch
> lib-radix_tree-tree-node-interface-fix.patch
> mm-keep-page-cache-radix-tree-nodes-in-check.patch
> mm-keep-page-cache-radix-tree-nodes-in-check-fix.patch
> mm-keep-page-cache-radix-tree-nodes-in-check-fix-fix.patch
> mm-keep-page-cache-radix-tree-nodes-in-check-fix-fix-fix.patch
> pagewalk-update-page-table-walker-core.patch
> pagewalk-add-walk_page_vma.patch
> smaps-redefine-callback-functions-for-page-table-walker.patch
> clear_refs-redefine-callback-functions-for-page-table-walker.patch
> pagemap-redefine-callback-functions-for-page-table-walker.patch
> numa_maps-redefine-callback-functions-for-page-table-walker.patch
> memcg-redefine-callback-functions-for-page-table-walker.patch
> madvise-redefine-callback-functions-for-page-table-walker.patch
> arch-powerpc-mm-subpage-protc-use-walk_page_vma-instead-of-walk_page_range.patch
> pagewalk-remove-argument-hmask-from-hugetlb_entry.patch
> mempolicy-apply-page-table-walker-on-queue_pages_range.patch
> drop_caches-add-some-documentation-and-info-message.patch
> memcg-slab-never-try-to-merge-memcg-caches.patch
> memcg-slab-cleanup-memcg-cache-creation.patch
> memcg-slab-separate-memcg-vs-root-cache-creation-paths.patch
> memcg-slab-unregister-cache-from-memcg-before-starting-to-destroy-it.patch
> memcg-slab-do-not-destroy-children-caches-if-parent-has-aliases.patch
> slub-adjust-memcg-caches-when-creating-cache-alias.patch
> slub-rework-sysfs-layout-for-memcg-caches.patch
> mm-fix-gfp_thisnode-callers-and-clarify.patch
> mm-revert-thp-make-madv_hugepage-check-for-mm-def_flags.patch
> mm-thp-add-vm_init_def_mask-and-prctl_thp_disable.patch
> exec-kill-the-unnecessary-mm-def_flags-setting-in-load_elf_binary.patch
> fork-collapse-copy_flags-into-copy_process.patch
> mm-mempolicy-rename-slab_node-for-clarity.patch
> mm-mempolicy-remove-per-process-flag.patch
> res_counter-remove-interface-for-locked-charging-and-uncharging.patch
> linux-next.patch
> debugging-keep-track-of-page-owners.patch
> 
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